In a semiconductor manufacturing factory, a semiconductor substrate is accommodated in a transfer container, and the transfer container is transferred to a semiconductor manufacturing apparatus by an automated guided vehicle (AGV) or an overhead transfer device (OHT). The semiconductor manufacturing apparatus includes a loading/unloading port for loading/unloading the semiconductor into/from the transfer container from/into the apparatus and a processing block for performing a process onto the semiconductor substrate (wafer). The transfer container is configured as an airtight container including a cover body at a front surface of a container main body. At an outer surface of the cover body, two key holes for separating the cover body from the container main body are formed. Within the container main body, multiple sheets of the wafer are stored in the form of shelves.
The loading/unloading port is typically called a “load port”, and includes a stage on which the transfer container is mounted from the outside and a device configured to separate the cover body. The semiconductor manufacturing apparatus includes a film forming apparatus, a mask pattern forming apparatus, an etching apparatus, and a cleaning apparatus to be appropriately used for respective processes of a semiconductor manufacturing process. The semiconductor substrate is transferred between these apparatuses in sequence by the transfer container.
Typically, in the transfer container, the wafer is stored horizontally. However, as described below, when the cover body is separated, the wafer may be inclined within the container main body. In this case, the wafer may be damaged by a wafer moving and mounting device when the wafer moving and mounting device enters into the transfer container. Further, when the cover body is separated, the wafer may be protruded from the container main body. In this case, the substrate may not be transferred by the wafer moving and mounting device to a preset target position, or the wafer may fall down from the moving and mounting device. Patent Document 1 describes that a positioning error correction member is provided at a moving and mounting device. However, it requires high costs to provide the correction member as such, and there is no consideration on inclination of a substrate. Thus, it is not sufficient to solve the above-described problem. Further, Patent Document 2 describes a technology of detecting a protrusion of a substrate from a transfer container and stopping an unloading of the substrate when the protrusion is detected. However, if the unloading is stopped as such, production efficiency of a semiconductor device is decreased.
Patent Document 1: Japanese Patent Laid-open Publication No. H11-011663
Patent Document 2: Japanese Patent Laid-open Publication No. H04-010639